[leetcode/java] 287. Find the Duplicate Number

Map을 이용한 풀이

class Solution {
    
    public int findDuplicate(int[] nums) {
        int duplicateNumber = 0;
        int numsLength = nums.length;
        
        Map<Integer, Integer> map = new HashMap<>();
        
        for (int i : nums) {
            map.put(i, map.getOrDefault(i, 0) + 1);
            
            if (map.get(i) > 1) duplicateNumber = i;
        }
        
        return duplicateNumber;
    }
    
}